Research Methods

Aim - General statement of what the researcher intends to do

Hypothesis - Clear, precise and testable statement - relationship between variables

Directional Hypothesis - State the direction in which the change will take place

Non-directional Hypothesis - There will be a change

Null Hypothesis - Results will be due to chance not to the manipulation of the IV - IV does not affect the DV

• Placed in a lab
• Researcher manipulates independent variable

Strengths -

• High Control
• Easy to replicate

Weakenesses -

• Artificial conditions - lacks ecological validity

• Participants in natural envrionment
• Researcher manipulates independent variable

Strengths -

• Increase ecological validity
• Participants unaware of testing - less demand characteristics

Weaknessess -

• Loss of control
• Hard to replicate 

• Researcher does not manipulate IV

Strengths -

• Increase ecological validity
• Reduced demand characteristics

Weaknessess -

• No control
• Harder to replicate

• Not able to randomally allocate the participants
• IV is a feature of participants - Male / Female eg

Strengths -

• Increased ecological validity

Weaknessess -

• Aware participants are being studied - lacks internal validity

• Random
• Volunteer
• Systematic
• Stratified
• Opportunity

• List is made of every member of the target population and the names are selected randomly
• Drawing out of a hat or using computer programme

Strengths -

• Least biased
• Equal chance for everyone

Weaknessess -

• Expensive
• Time consuming

• Select people available at the time of the study
• Asking people in the street

Strengths -

• Easiest method
• Cheapest
• Least time consuming

Weaknessess -

• Biased - taking frrom only a part of target population

• People are recruited by asking them to volunteer to take part in the study
• Advert in newspaper, internet or notice boards

Strengths -

• More representative - more categries of people

Weaknessess -

• Biased - participants likely to have volunteered as they are intrested in the topic

• Make a list of the target population and select every nth person on the list
• Example - every tenth person

Strengths -

• Representative sample

Weaknessess -

• Expensive
• Time consuming - difficult to get name of every member

• Identify catogries in the target population
• Select participants to match their occurrence in target population

Strengths -

• Represnetative - all the subgroups in the target population are represnted

Weaknessess -

• Time consuming
• Difficult

• Identify catogries in the target population
• Select participants to match their occurrence in target population

Strengths -

• Represnetative - all the subgroups in the target population are represnted

Weaknessess -

• Time consuming
• Difficult

Individual Characteristics -

• Characteristics of participants which might influence the way they perform in an experiment

Demand Characteristics -

• Clues in an experiment which suggest to the participant the purpose of the research
• Affeced by their surroundings

Order Effect -

• Participants might become tired and bored
• Affect thier performance - act as confounding variable

Practice Effect -

Participants have done one condition they might perfrom better in the second condition as they know the task

• Independent Measures Design
• Repeated Measures Design
• Matched Pairs Design

• Participants only take part in one condition of the experiment (2 seperate groups)
• Allocated randomly to the conditions

Strengths -

• Avoids practice effect and order effect
• Reduces the risk of demand characteristics

Weaknesses -

• More participants are needed
• Individual characteristics may influence the results

• Participants take part in both conditions of the experiment (1 group)

Strengths -

• Requires less participants than IMD
• Less influence of individual characteristics

Weaknessess -

• Order effect and practice effect are likley to influence the results
• Demand characteristcs may influence the results

• Participants are matched in each condition for characteristics that may have an effect on thier perfromance

Strenghts -

• Avoids order effect and practive effect
• Reduces the influence of individual characteritics

Weaknessess -

• Very time consuming
• Impossible to match participants exactly - influence of individual characteristics